1. Field of the Invention
The present invention relates to an apparatus for automatically supplying a lubricant oil to an internal combustion engine for a vehicle by detecting a shortage in the amount of the oil. The apparatus is suitably applied to a one-box type vehicle wherein the engine body is arranged under a driver's seat in a vehicle compartment, and therefore, it is difficult to service the engine for maintenance purposes.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 62-93417 proposes an automated apparatus for supplying lubrication oil in an internal combustion engine for a vehicle, whereby an automatic supply of lubricant oil is carried out when a lowering of the oil level with respect to a predetermined level in an oil pan is detected after a predetermined time has elapsed from the time of stopping the engine, which has been operated for at least a time in which the temperature of the oil is increased, which determines the viscosity of the oil. A timer circuit is provided for continuing the operation of a control circuit, which allows a detection of an oil level in the oil pan for a predetermined time after the ignition key switch is made OFF for stopping the engine. As a result, the measurement of the oil level is carried out while the oil level in the oil pan is in a stabilized condition, for a precise detection of any shortage in the amount of oil in the oil pan.
In the prior art, to allow enough time to pass for the oil level in the oil pan to settle after the engine is stopped, a timer means is provided for detecting a predetermined time after the ignition key switch is made OFF, and a detection of the oil level in the oil pan is carried out after the lapse of this predetermined time. Namely, the control circuit must continue to operate after the ignition key switch is made OFF, so that the detection of the oil level can be executed after the lapse of the predetermined time, after which the control circuit is made OFF by the timer circuit. This means that the prior art requires extra parts such as a timer for energizing the control circuit after the ignition key switch is made OFF, and that the load on the battery is increased because the control circuit is energized after the engine is stopped.